Furnace



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URNAC 2 Sheets-s 1 Filed June 7 1928 m ===w//%F M w NE W MM w :VLZ W m7 A KN NW EEC:

F. MENNE Dec. 10, 1929.

FURNACE 2 Sheets-Sheet 2 Filed June '7, 1928 INVENTOR Fe/Tz MEN/v: B;

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yWx 6% ATTORNEYS Patented Dec. 1D, 1929 UNITED STATES PATENT OFFICE HOEVEL, OF NEW YORK, N.

FURNACE Application filed June 7, 1928, Serial No.

My invention relates to furnaces of the type I in which the material to be exposed to heat travels longitudinally of a horizontal or ap proximately horizontal treatment chamber. 11 a. certain species of furnaces of this type, the material is advanced intermittently by periodically raising it off the bottom of the chamber, advancing the material in this raised position toward the outlet of the chamber, and then lowering the material until it again comes to rest on the bottom of the treat ment chamber. My present invention has for its object to provide a simple and reliable construction of the character indicated above, in which the parts of the operating mechanism will be protected against the injurious effects of excessive heat, and in which the parts employed for lifting and feeding the material will be connected with the operating mechanism in such a manner as to obtain a proper bracing and particularly to guard against any lateral tilting of such lifting and feeding members. While the specific embodiment of my invention illustrated by the accompanying drawings combines the several advan tages indicated above, I desire it to be understood that certain features might be modified without departing from the nature of my invention as set forth in the appended claims, and that it is not necessary for a furnace, in order to come within the scope of my invention, that it should possess all the advantages of the particular embodiment illustrated.

In the accompanying drawing Fig. 1 is a longitudinal section of a furnace embodying my invention, taken on line 11 of Fig. 2 the latter being a plan view with parts in section, and Fig. 3 is a transverse vertical section on line 33 of Fig. 2.

At each side of the furnace, and exteriorly of the side walls 10 of the furnace body, I have shown a pair of carriages or slides, each pair comprising a lower slide 11 movable along; stationary rails 12 extending lengthwise of the furnace, and an upper slide 13 resting on the lower slide and movable not only lengthwise of the furnace, but also up and down. At its end portions, each lower slide is provided with parallel inclines 15 on 283,503, and in Germany June 24, 1927.

which are adapted to travel rollers 16 jour naled on the corresponding upper slide. When the upper slide is in its lower position, its rollers 16 are at the bottom of the inclines, on horizontal track portions 17 adjacent to such inclines. At their upper portions, the slides or carriages 13 are connected by cross bars 18 extending under the bottom of the furnace body and supporting a movable bottom 19 fitted lengthwise into a longitudinal channel 20 of the furnace body. The detail construction of the furnace and of the movable bottom 19 may be of any approved character, for instance, as shown in my pending applicain the United the portions of the furnace body at each side of the channel 20, while the central portions of said articles are engaged and supported at times, by the movable bottom 19. Preferably the article-supporting surfaces of said bottom end of the furnace body are provided with pipes 21, 22 projecting from said sur faces and containing water or other circulating fluid, for cooling. The pipes 21 also raise the articles off said surfaces, so that the'hot gases, entering at 23 and traveling lengthwise of the furnace in a direction opposite to the progress of the articles, will have free access to the major portion of the bottom surfaces of the articles.

Preferably the movable bottom 19 rests loosely on the cross bars 18; this will enable .the bottom to be' removed from the furnace for repairs, etc., by simply sliding it out. Another advantage of this loose connection is found in the fact that the movable bottom may be adjusted laterally of the furnace to the proper position at the center of the channel 20. Should the bottom accidentally or through negligence be sufliciently ofi" center to rub against one side of the channel 20, such friction will tend to push the bottom 19 away from said side and toward the proper position, so that such friction will be reduced automatically, or done away with entirely.

The pipes 21 are shown as projecting lengthwise from h b t m 19 at the end nearest the inlet 23 for the heating medium (which is the end at which the material under treatment leaves the furnace). Thus any grit or particles which have come off the material under treatment, or that may be carried into the furnace by the heating medium entering at 23, will have an opportunity to be eliminated by falling down between such longitudinally-projecting ends of the pipes 21. Any usual or approved means (sliding doors, etc.) may be employed for closing the furnace at the openings through which the material enters and leaves respectively.

I have shown the following mechanism for imparting the desired motion to the cross bars 18 and to the movable bottom 19 resting thereon: Exteriorly of the furnace, at the end through which the material enters, a trans verse shaft 24 is journaled in suitable bearings 25, and this shaft carries two pairs of eccentrics 26 and 27 respectively, those of the same pair being of like position and connected with the same slide or carriage, by eccentric rods 28 and 29 respectively, pivoted at 30 and 31 respectively to the upper and the lower carriage 13 and 11 respectively. The eccentrics of one pair are offset with respect to those of the other pair.

The shaft 24 is driven in any suitable man-- ner, for instance by means of an electric motor 32, preferably through the medium of a clutch 33, 34. In many cases, I consider it desirable to provide means for stopping the shaft 24 automatically after a complete revolution, while allowing the motor 32 to,run continuously. For this purpose, the clutch member 33 driven from the motor continuously by means of gearing 35. may be mounted loosely on the shaft 24, while the other clutch member 34 is held to rotate with the shaft (say, by a spline and groove), but slidable lengthwise thereof into and out of engagement with the driving clutch member 33. A spring 36 tends to move the clutch member 34 away from the companion member 33. On the clutch member 34 is a pin 37 which, when the shaft 24 has come to a stop, registers with a slot or opening 38' in a stationary guide or collar 38. At 39 I have indicated a lever of any suitable construction for enabling the operator to throw the clutch'member 34 into engagement with the companion member 33. When the shaft 24 is stationary, the pin 37 is in its outer position. As the operator throws the clutch member-34 inward,'the pin 37 will pass inwardly out of the slot 38, and as soon as the shaft 24 begins to rotate, the pin 37 will be carried out of registry with the slot 38, and the guide 38, against the inner surface of which said pin will bear, under the influence of the spring 36, will act as a stop to prevent outward movement of said pin and of the clutch member 34, so that the clutch will remain engaged. At the end of the com- I to revolution, the pin 37 will again register with the slot 38", and the spring 36 will automatically move the clutch member 34 away from the clutch member 33, the pin 37 passing out of contact with the inside of the stop orguide 38, to the initial outer position. The shaft 24 is thus arrested automatically at the end of a complete revolution, but the rotation of the motor 32 is not interrupted.

The. feeding of the material lengthwise of the furnace is effected during the rotation of the shaft 24 by a four-step motion of a character which is well-known in this art, it being understood that my invention provides a novel mechanism and arrangement for Ohtaining such four-motion feed.

In the initial position, the slides 11, 13 are nearest to the shaft 24 (farthest from the outlet through which the material leaves the furnace), and the upper slide is in its lower position; one end of the movable bottom 19 projects beyond the entrance end of the fur-- nace (at the right in Fig. 1). On this projecting end I place the material to be treated, either in the shape of a bundle, as indicated at A, or in some cases the material might be put in trays or other holders. When the shaft 24 begins to revolve, the first effect will be to lift the upper slide 13 and the bottom 19 by the action of the longitudinally moving inclines 15 on the rollers 16 until the upper surface of said bottom, and the material thereon,are above the level of the material-supporting surface in the interior of the furnace body. Then, with the bottom in this raised position, both slides 11, 13 move away from ,the shaft 24, thus carrying the material previously deposited on the projecting portion of the bottom 19. into the furnace. During the third movement which then follows, the lower slide alone is moved lengthwise of the furnace (away from the shaft 24), and by the co-operation of the inclines 15 with the rollers 16 the upper slide 13 is allowed to drop to its lower position, whereby the material is transferred from the bottom 19 to the supporting surfaces of the furnace body, at each side of the channel 20. Finally, the upper slide 13, in the lower position in which it is clear of the material deposited on said supporting surfaces, is moved lengthwise of the furnace together with the lower slide 11, toward the shaft 24, to the initial position. At this moment, the shaft has completed a revolution, and is stopped automatically by the mechanism described above.

It will be noted that the points at which the ends of a cross bar 18. are connected with the two upper slides 13, are-relatively far apart, thus affording a broad base or support for the movable bottom 19 and guarding against the lateral tiltingjjof the cross bars 18 and of said bottom. The slides 11, 13 and the eccentric mechanism with which they 1. 1 99nne ted, are at the sides of the furnaces exteriorly thereof, and away from the region of greatest heat, so that such mechanism will not be subject to material distortion and excessive wear. The eccentrics which effect the longitudinal movement of the upper and the lower slides respectively, may be set very close together, almost in the same vertical plane, thus obtaining not only a compact construction, but a more reliable operation. Any material that may drop through the channel 20 of the furnace will fall clear of the slides and their operating 18 are directly below said channel.

I claim:

A furnace having a longitudinal passage, parallel cooled pipes in said furnace extending lengthwise of said passage at opposite sides thereof, a loose bottom in said passage movable therein both lengthwise of the furnace and up and down relatively thereto, parallel cooled pipes fixed on the upper surface of said bottom, said cooled pipes constituting supports for the articles to be passed through the furnace, a pair of superposed carriers located at each side of the furnace exteriorly thereof, co-operating inclinations and rollers on said carriers whereby movement of my hand.

FRITZ MEN N E.

mechanism, since only the smallcentral-portions of the cross bars one carrier lengthwise of the other Wlll cause upward or downward loose bottom, and unitary 

